def reverse_words(sentence):
    words = sentence.split() # 用split()分割
    reversed_words = words[::-1] # 反转单词列表

    reversed_sentence = ' '.join(reversed_words)
    return reversed_sentence

# 测试示例
sentence = "hello xiao mi"
reversed_sentence = reverse_words(sentence)
print(reversed_sentence)  
# 输出: "mi xiao hello"